I personally buy all my cables and connectors from monoprice and I am very,very pleased with their customer service, quality and price.
With RCA cables you will not notice that much difference between vendors; difference usually in looks, cable sheating or quality of end connections. HDMI cables and video cables is where you sometimes see differences.
Haivng said that buy good cables, such as Monoprice, but not expensive ones and you will be fine
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.
In the past, I have done business with Crutchfield, mainly car stereo when cars came with crappy radios, and their quality and customer service is good but their prices are no bargain.
Later,
NJ
P.S.- Monoprice makes some great locking banana plugs; my recommended way ( and many others
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) to connect speakers to the AVR.
Hope this helps